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Diffstat (limited to 'sandbox/src/interception.h')
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diff --git a/sandbox/src/interception.h b/sandbox/src/interception.h new file mode 100644 index 0000000..3367a53 --- /dev/null +++ b/sandbox/src/interception.h @@ -0,0 +1,229 @@ +// Copyright 2008, Google Inc. +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +// Defines InterceptionManager, the class in charge of setting up interceptions +// for the sandboxed process. For more datails see +// http://wiki/Main/ChromeSandboxInterceptionDesign + +#ifndef SANDBOX_SRC_INTERCEPTION_H__ +#define SANDBOX_SRC_INTERCEPTION_H__ + +#include <list> +#include <string> + +#include "base/basictypes.h" +#include "sandbox/src/sandbox_types.h" + +#pragma warning(push, 3) +#include "testing/gtest/include/gtest/gtest.h" +#pragma warning(pop) + +namespace sandbox { + +class TargetProcess; + +// Internal structures used for communication between the broker and the target. +struct DllPatchInfo; +struct DllInterceptionData; + +// The InterceptionManager executes on the parent application, and it is in +// charge of setting up the desired interceptions, and placing the Interception +// Agent into the child application. +// +// The exposed API consists of two methods: AddToPatchedFunctions to set up a +// particular interception, and InitializeInterceptions to actually go ahead and +// perform all interceptions and transfer data to the child application. +// +// The typical usage is something like this: +// +// InterceptionManager interception_manager(child); +// if (!interception_manager.AddToPatchedFunctions( +// L"ntdll.dll", "NtCreateFile", +// sandbox::INTERCEPTION_SERVICE_CALL, &MyNtCreateFile)) +// return false; +// +// if (!interception_manager.AddToPatchedFunctions( +// L"kernel32.dll", "CreateDirectoryW", +// sandbox::INTERCEPTION_EAT, L"MyCreateDirectoryW@12")) +// return false; +// +// if (!interception_manager.InitializeInterceptions()) { +// DWORD error = ::GetLastError(); +// return false; +// } +// +// Any required syncronization must be performed outside this class. Also, it is +// not possible to perform further interceptions after InitializeInterceptions +// is called. +// +class InterceptionManager { + // The unit test will access private members. + FRIEND_TEST(InterceptionManagerTest, BufferLayout); + + public: + // An interception manager performs interceptions on a given child process. + // If we are allowed to intercept functions that have been patched by somebody + // else, relaxed should be set to true. + // Note: We increase the child's reference count internally. + InterceptionManager(TargetProcess* child_process, bool relaxed); + ~InterceptionManager(); + + // Patches function_name inside dll_name to point to replacement_code_address. + // function_name has to be an exported symbol of dll_name. + // Returns true on success. + // + // The new function should match the prototype and calling convention of the + // function to intercept except for one extra argument (the first one) that + // contains a pointer to the original function, to simplify the development + // of interceptors. + // + // For example, to intercept NtClose, the following code could be used: + // + // typedef NTSTATUS (WINAPI *NtCloseFunction) (IN HANDLE Handle); + // NTSTATUS WINAPI MyNtCose (IN NtCloseFunction OriginalClose, + // IN HANDLE Handle) { + // // do something + // // call the original function + // return OriginalClose(Handle); + // } + bool AddToPatchedFunctions(const wchar_t* dll_name, + const char* function_name, + InterceptionType interception_type, + const void* replacement_code_address); + + // Patches function_name inside dll_name to point to + // replacement_function_name. + bool AddToPatchedFunctions(const wchar_t* dll_name, + const char* function_name, + InterceptionType interception_type, + const char* replacement_function_name); + + // Initializes all interceptions on the client. + // Returns true on success. + // + // The child process must be created suspended, and cannot be resumed until + // after this method returns. In addition, no action should be perfomed on + // the child that may cause it to resume momentarily, such as injecting + // threads or APCs. + // + // This function must be called only once, after all interceptions have been + // set up using AddToPatchedFunctions. + bool InitializeInterceptions(); + + private: + // Used to store the interception information until the actual set-up. + struct InterceptionData { + InterceptionType type; // Interception type + std::wstring dll; // Name of dll to intercept + std::string function; // Name of function to intercept + std::string interceptor; // Name of interceptor function + const void* interceptor_address; // Interceptor's entry point + }; + + // Calculates the size of the required configuration buffer. + size_t GetBufferSize() const; + + // Rounds up the size of a given buffer, considering alignment (padding). + // value is the current size of the buffer, and alignment is specified in + // bytes. + static inline size_t RoundUpToMultiple(size_t value, size_t alignment) { + return ((value + alignment -1) / alignment) * alignment; + } + + // Sets up a given buffer with all the information that has to be transfered + // to the child. + // Returns true on success. + // + // The buffer size should be at least the value returned by GetBufferSize + bool SetupConfigBuffer(void* buffer, size_t buffer_bytes); + + // Fills up the part of the transfer buffer that corresponds to information + // about one dll to patch. + // data is the first recorded interception for this dll. + // Returns true on success. + // + // On successful return, buffer will be advanced from it's current position + // to the point where the next block of configuration data should be written + // (the actual interception info), and the current size of the buffer will + // decrease to account the space used by this method. + bool SetupDllInfo(const InterceptionData& data, + void** buffer, size_t* buffer_bytes) const; + + // Fills up the part of the transfer buffer that corresponds to a single + // function to patch. + // dll_info points to the dll being updated with the interception stored on + // data. The buffer pointer and remaining size are updated by this call. + // Returns true on success. + bool SetupInterceptionInfo(const InterceptionData& data, void** buffer, + size_t* buffer_bytes, + DllPatchInfo* dll_info) const; + + // Returns true if this interception is to be performed by the child + // as opposed to from the parent. + bool IsInterceptionPerformedByChild(const InterceptionData& data) const; + + // Allocates a buffer on the child's address space (returned on + // remote_buffer), and fills it with the contents of a local buffer. + // Returns true on success. + bool CopyDataToChild(const void* local_buffer, size_t buffer_bytes, + void** remote_buffer) const; + + // Performs the cold patch (from the parent) of ntdll.dll. + // Returns true on success. + // + // This method will inser aditional interceptions to launch the interceptor + // agent on the child process, if there are additional interceptions to do. + bool PatchNtdll(bool hot_patch_needed); + + // Peforms the actual interceptions on ntdll. + // thunks is the memory to store all the thunks for this dll (on the child), + // and dll_data is a local buffer to hold global dll interception info. + // Returns true on success. + bool PatchClientFunctions(DllInterceptionData* thunks, + size_t thunk_bytes, + DllInterceptionData* dll_data); + + // The process to intercept. + TargetProcess* child_; + // Holds all interception info until the call to initialize (perform the + // actual patch). + std::list<InterceptionData> interceptions_; + + // Keep track of patches added by name. + bool names_used_; + + // true if we are allowed to patch already-patched functions. + bool relaxed_; + + DISALLOW_EVIL_CONSTRUCTORS(InterceptionManager); +}; + +} // namespace sandbox + +#endif // SANDBOX_SRC_INTERCEPTION_H__ |